• Pediatric Infection and Vaccine
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• v.23 no.1
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• pp.31-39
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• 2016

Purpose: The aim of this study was to investigate the prognostic factors for Pneumocystis jirovecii pneumonia (PCP) and to evaluate the influence of PCP prophylaxis in pediatric patients. Methods: From January 2002 to April 2015, patients aged <18 years with a diagnosis of confirmed PCP at our institute were reviewed retrospectively. Clinical characteristics and outcomes were compared according to the groups with or without PCP prophylaxis. Risk factors associated with PCP-related death were analyzed by logistic regression analysis. Results: During study period, a total of 24 patients were diagnosed with PCP by immunofluorescence assay and/or PCR. The median age of the patients was 5 years (range, 3 months-18 years) and 23 (96%) had immunocompromised conditions including hematologic disorders with or without hematopoietic stem cell transplantation (n=15), solid organ transplantation (n=4), and primary immune deficiency (n=4). Most common presenting symptoms were tachypnea and cough (92%, each). At the time of diagnosis, 79% (19/24) and 25% (6/24) suffered from respiratory failure and multi-organ dysfunction syndrome (MODS), respectively. Mechanical ventilation was required in 8 (33%) patients and 5 (21%) patients died of PCP. Multivariate analysis showed that MODS at initial presentation was an indicator of poor prognosis (OR, 17.1 [95% CI 1.13-257.67]; P=0.04). Compared to the patients without PCP prophylaxis, the frequency of MODS at diagnosis, need for mechanical ventilation and length of hospital days were significantly less common in the children who received PCP prophylaxis. Conclusions: MODS at presentation was a significant predictor for poor outcome and PCP prophylaxis could alleviate the clinical courses of pediatric PCP. Prospective study will be mandatory to determine the risk factors for development and deterioration of PCP in children.

• Radiation Oncology Journal
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• v.28 no.1
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• pp.23-31
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• 2010

Purpose: To evaluate the relationship between the normal tissue complication probability (NTCP) of 3-dimensional (3-D) radiotherapy and the radiographic parameters of 2-dimensional (2-D) radiotherapy such as central lung distance (CLD) and maximal heart distance (MHD). Materials and Methods: We analyzed 110 patients who were treated with postoperative radiotherapy for breast cancer. A two-field tangential technique, a three-field technique, and the reverse hockey stick method were used. The radiation dose administered to whole breast or the chest wall was 50.4 Gy, whereas a 45 Gy was administered to the supraclavicular field. The NTCPs of the heart and lung were calculated by the modified Lyman model and the relative seriality model. Results: For all patients, the NTCPs of radiation-induced pneumonitis and cardiac mortality were 0.5% and 0.7%, respectively. The NTCP of radiation-induced pneumonitis was higher in patients treated with the reverse hockey stick method than in those treated by other two techniques (0.0%, 0.0%, 3.1%, p<0.001). The NTCP of radiation-induced pneumonitis increased with CLD. The NTCP of cardiac mortality increased with MHD ($R^2=0.808$). Conclusion: We found a close correlation between the NTCP of 3-D radiotherapy and 2-D radiographic parameters. Our results are useful to reanalyze the previous 2-D based clinical reports about breast radiation therapy complications as a viewpoint of NTCP.

• Journal of Chest Surgery
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• v.36 no.10
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• pp.728-733
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• 2003

Background: The aim of the current study was to assess the effects of total arterial myocardial revascularization (TAMR) with bilateral internal mammary arteries. Material and Method: 139 consecutive patients who underwent off pump coronary artery bypass surgery from January 2000 to December 2001 were included in the current retrospective study. Patients were divided into those receiving bilateral internal mammary artery, BITA (n=85) and those receiving single internal mammary artery, SITA (n=54). Result: There was only one death in each group. No significant differences were noted in the total ICU and hospital stay; 2.4$\pm$1.7 and 11.2$\pm$17.7 days, in the BITA group, respectively and 2.8$\pm$2.7 and 9.7$\pm$7.1 days in the SITA group, respectively (P>0.05). The mean number of distal anastomosis of 3.9$\pm$0.7 was slightly higher in the SITA group compared to the SITA group, which was 3.1$\pm$0.8. Myocardial infarction occurred in 7 patients (BITA group: 2, SITA group: 5) and deep sternal infection necessitating reoperation occurred in 4 patients (BITA group: 3, SITA group: 1). Coronary angiogram was performed in the immediate postoperative period in 104 patients (BITA group: 64/85, SITA group: 40/54). Of these patients, stenosis in the LAD anastomosis site occurred in 4 patients (BITA group: 2, SITA group: 2). A total of 8 anastomotic sites were stenotic in the entire series of which percutaneous intervention was performed in 3 patients and none required reoperative coronary artery bypass. Conclusion: The results of the current data did not show a significant difference in patiency rate with bilateral internal mammary artery use for CABG supporting the feasibility of its use as a viable alternative method for TAMR.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.4
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• pp.321-337
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• 2010

Long-term trends and distribution patterns of water quality were investigated in the Mokpo coastal areas of the Yellow Sea, Korea from 1979 to 2009. Water samples were collected at 5 stations and physicochemical parameters were analyzed including water temperature, salinity, suspended solids (SS), chemical oxygen demand (COD), dissolved oxygen (DO) and nutrients. Spatial distribution patterns of temperature, pH and DO were not clear among stations but the seasonal variations were distinct except ammonium. The trend analysis by principal component analysis (PCA) during 30 years revealed the significant variations in water quality in the study area. Spatial water qualities were discriminated into 3 clusters by PCA; station cluster 1, 2~4, and 5. Annual water qualities were clearly discriminated into 4 surface water clusters and 2 bottom water clusters by PCA. By this multi-variate analysis, the annual trends were summarized as the followings; water temperature, pH and COD tended to increase from late 1980's, salinity to decrease, phosphate to increase from 1994 and dissolved inorganic nitrogen to increase, due to the input of fresh water same as shown in Kyoungin coastal area, Asan coastal area, Choensoo bay and Gunsan coastal area.

• Korean journal of applied entomology
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• v.50 no.1
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• pp.47-53
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• 2011

The seasonal occurrence of Riptortus pedestris Fabricius was investigated using pheromone traps baited with its aggregation pheromone in the fields with various crop composition (mixture culture of barley and hairy vetch in Asan, Chungnam; monoculture of hairy vetch in Yuseung, Daejeon) from mid-May to mid-July of seed gathering season in 2010. The invasion of R. pedestris into the experimental fields began to increase rapidly from late-June in which period hairy vetch and barley reach the beginning of seed formation stage. After seed gathering season in mid-July, the invasion rate of R. pedestris decreased, and the activity was continually observed till early-November. In addition to dominant R. pedestris species, 33 species of hemiptera including Apolyaus watajii, Dolycoris baccarum, Adelphocoris suturalis, and Yemma exlis were collected, which indicated abundant species diversity in the hairy vetch fields. In the laboratory, R. pedestris did not developed successfully to adult stage on food sources of hairy vetch, with decreasing survival rate after 4th instar and the failure of emergence to adult stage. Also, R. pedestris showed higher preference on soybeans than hairy vetch. Consequently, hairy vetch may be not true host for the development and survival of R. pedestris. It is considered that R. pedestris is a temporary visitor at the season of seed formation in hairy vetch fields.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.3
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• pp.81-85
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• 2009

Purpose: The examination of nuclear medicine observes the change in accordance with the time elapsed in the same region purposed and there are many examinations to acquire the image during the same term. At this time, the same parameter should be applied. The hepatobiliary scan, lung scan etc, are the acquired examination in the divided time with a regular term. Pre-set time that is applied in continued next image is set in order to acquire the fixed counts. The same scan time should be applied for each image. This study will look for the rational plan and analyze the change of scan time in accordance with the time of the decision of scan time at examination that pre-set time is applied. Methods: The hapatobiliary scan that use the radio pharmaceutical $^{99m}Tc$-mebrofenin is choosed as compensation from Jan. 2009 to Mar. 2009 in the department of nuclear medicine in ASAN MEDICAL CENTER. Scan is started after 5 minutes from when 222 MBq (6 mCi) is injected to patient. We let patient stand up between both detectors, and possibly close to the front of detector. When scan time reach 10%, 25%, 50%, 75% of total scan time, we measured the expected total scan time. After finishing all of scan, we compared the total scan time and the expected total scan time, while image is acquiring. and we observed the change of scan time in accordance with radio activity by using phantom. Results: After starting scan, a difference of when scan time reach 10%, 25%, 50%, 75% of total scan time is that the biggest difference is 5 seconds on 10%. There statistically is difference between 25% (t:2.88, p<0.01) and 50% (t:2.05, p<0.01). Conclusions: When the same the scan time is applied in the examination that acquire the many frame, concluding the same scan time has a important effect on a quantitative analysis. Although method that decide the scan time after finish all of the examinations, there is a few problem to apply practical affairs. This may cause an inaccurate result on the examination that need a quantitative analysis. We think that operator should try to improve it. At least, after reach 50% of total scan time, deciding the total scan time mean that you can minimize error of a quantitative analysis caused by unmatched scan time from a gap of image.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.3
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• pp.86-91
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• 2009

Purpose: The whole body scan in Nuclear Medicine is a widely accepted examination and procedure. Especially, it is mainly used in bone, I-131, MIBI, and HMPAO WBC scans. The diverse uses of the whole body scan range from the HMPAO WBC scan with a speed of 13cm/min, to a whole body bone scan using the Onco. Flash technique with a speed of 30cm/min. The accuracy of table movement has a strong correlation with the image quality, and inaccuracy of speed could negatively affect the image quality. The purpose of this study is to evaluate the accuracy of the table movement while considering the influence of the age of the equipment and the variability in the weight of the patients. Material and Methods: The study was conducted using two of Seoul Asan Medical Center's SIEMENS gamma cameras which are commonly used in our whole body study. The first one is the oldest gamma camera, an ECAM plus (installed in 2000), and the last is brand new one, a SYMBIA T2 (installed in 2008). Three trials were conducted with the tables moving at a different speed each time; 10, 15 and 30 cm/min. The tables' speeds were measured by checking how long it took for the table to move 10cm, and this was repeated every 10cm until the table reached 100 cm. With an average body weight of the patients of about 60~70 kg, the table speed was measured with weights of 0 kg, 66 kg and 110 kg placed on the table, then compared among conditions. Results: The coefficient of variance (CV) of the ECAM plus showed 1.23, 1.42, 2.02 respectively when the table movement speeds were set at 10, 15, and 30 centimeters per minute. Under the same conditions, the SYMBIA T2 showed 1.23, 1.83 and 2.28 respectively. As table movement speed more, the variance of CV as the speed increases. When the patient body weight was set to 0, 66 and 110kg, the CV values of both cameras showed 0.96, 1.45, 2.08 (0 Kg), 1.32, 1.72, 2.27 (66 Kg) and 1.37, 1.73, 2.14 (110 Kg). There was no significant difference (p>0.05) in 95 percent of confidence intervals and measured CV values were acceptable. However, the CV value of the SYMBIA T2 was relatively larger than the ECAM plus. Conclusion: The scan speed of the whole body scan is predetermined based on which examination is being performed. It is possible for the accuracy of the speed to be affected, such as the age of the equipment, the state of the bearings or the weight of a patient. These factors can have a negative impact on the diagnostic consistency and the image quality. Therefore, periodic quality control should be needed on the gamma cameras currently being used, focusing on the table movement speed in order to maintain accuracy and reproducibility.

• Clinical and Experimental Pediatrics
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• v.48 no.11
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• pp.1212-1218
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• 2005

Purpose : Forward pulmonary blood flow may be absent in some neonates with Ebstein's anomaly by anatomical or functional pulmonary atresia in association with the elevated pulmonary vascular resistance, patent ductus arteriosus and tricuspid regurgitation. We reviewed the presentation and outcomes of symptomatic neonates with Ebstein's anomaly focusing on the pulmonary atresia. Methods : Clinical presentation and outcome of 15 symptomatic neonates with Ebstein's anomaly seen at Asan medical center from 1998 to 2004 were reviewed. Results : Ten(67%) of 15 patients showed no forward pulmonary blood flow and 6 of them had functional pulmonary atresia. $O_2$ saturation and pH were lower and cardiothoracic(CT) ratio in chest radiography was more increased in the patients with pulmonary atresia than in the patients without pulmonary atresia(P<0.05). pH and CT ratio were not different between the anatomical and functional pulmonary atresia group, but $O_2$ saturation was lower in functional atresia group(P<0.05). 13 patients(87%) were managed with $PGE_1$. 4 of 6 patients with functional pulmonary atresia were treated with inhaled nitric oxide. Surgery was performed in 1 of 5 patients without pulmonary atresia and in 8 of 10 patients with pulmonary atresia during follow-up period(mean 37 months). 3 patients(20%) died and none of patients without pulmonary atresia died. Conclusion : We found that most symptomatic neonates with Ebstein's anomaly had functional or anatomical pulmonary atresia. The neonates with Ebstein's anomaly who had no forward pulmonary blood flow were more symptomatic and needed surgery earlier. Further studies will be needed to distinguish effectively functional and anatomical pulmonary atresia and to manage appropriately neonates with functional atresia.

• Clinical and Experimental Pediatrics
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• v.48 no.1
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• pp.68-74
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• 2005

Purpose : There is growing use of continuous renal replacement therapy(CRRT) for pediatric patients, but reports about the use and outcome of CRRT in children is rare in Korea. We report our experiences of CRRT in critically ill pediatric patients. Methods : We reviewed the medical records of 23 pediatric patients who underwent CRRT at Asan Medical Center between May 2001 and May 2004. We evaluated underlying diseases, clinical features, treatment courses, CRRT modalities and outcomes. Results : Ages ranged from three days to 16 years with a median of five years. Patients weighed 2.4 to 63.9 kg(median 23.0 kg; 10 patients ${\leq}20kg$). The underlying diseases were malignancy(nine cases), multiple organ dysfunction syndrome(five cases), hyperammonemia(four cases), acute renal failure associated with liver failure(three cases), dilated cardiomyopathy(one case) and congenital nephrotic syndrome(one case). Pediatric Risk of Mortality(PRISM) III score was $17.6{\pm}7.6$ and the mean number of failing organs was $3.0{\pm}1.7$. Duration of CRRT was one to 27 days(median : nine days). Eleven patients(47.8%) survived. Chronic renal failure developed in two cases, intracranial hemorrhage in one case, and chylothorax in one case among the survivors. PRISM III score and the number of vasopressor before the start of CRRT was significantly lower in the survivors($12.7{\pm}4.2$ and $0.9{\pm}1.1$) compared with nonsurvivors($22.1{\pm}7.8$ and $2.4{\pm}1.4$)(P<0.05). Conclusion : CRRT driven in venovenous mode is an effective and safe method of renal support for critically-ill infants and children to control fluid balance and metabolic derangement. Survival is affected by PRISM III score and the number of vasopressors at the initiation of CRRT.

• Clinical and Experimental Pediatrics
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• v.49 no.12
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• pp.1324-1328
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• 2006

Purpose : The object of this study was to determine the difference between two methods for myocardial performance index(MPI) in children, using the conventional and pulsed Doppler echocardiography. Methods : A total of 27 children with anatomically normal hearts were enrolled for the study. all were examined by conventional and pulsed Doppler echocardiography at Gangneung Asan Hospital between December, 2005 and February, 2006. First, we measured the time interval(a1) between the mitral inflows from apical 4-chamber view, and the ejection time(ET1) from apical 5-chamber view. And then, we calculated MPI1, isovolumic contraction time(ICT1) and isovolumic relaxation time (IRT1). Secondly, we measured ICT2, ET2 and IRT2 from apical 5-chamber view with a Dopper signal placed at just below junction between mitral and aortic valve at the same cardiac cycle. And then, we calculated MPI2. We compared MPI1 to MPI2. All MPIs were calculated by using the formula, MPI=(ICT+IRT)/ET. Results : The mean age was $5.7{\pm}2.2years$ old(M:F=15:12). The MPI2 was higher than MPI1: $0.277{\pm}0.083$ vs. $0.428{\pm}0.081$(MPI1 vs MPI2, P=0.000). Also, the ICT2 was higher than ICT1: $56{\pm}15msec$ vs $97{\pm}18msec$(ICT1 vs ICT2, P=0.000) and the IRT2 was higher than IRT1: $42{\pm}8msec$ vs $53{\pm}9msec$(IRT1 vs IRT2, P=0.000). But, the ET2 was lower than ET1: $260{\pm}16msec$ vs $254{\pm}14msec$ (ET1 vs ET2, P=0.01). There was, as well, positive linear correlation between MPI1 and MPI2. Conclusion : This study showed that there is a difference between MPI1 and MPI2 in connection with estimating methods. However, the two MPIs had a positive linear correlation. Judging from our results, the MPI of the new method might be a useful index of venticular global function in children.